1. Field of the Invention
The present invention pertains to floatable units with modifiable bow configurations and more particularly to such units which are capable of being modified to facilitate the travel of the hull along the surface of a body of water.
2. Description of the Prior Art
Structure is known which is associated with various types of vehicles which when either inflated or extended provides additional buoyancy for the vehicle to which the structure is attached. U.S. Pat. No. 1,180,013, Cook et al, for example, discloses an extendable telescoping vehicle nose section and slightly tapered. These telescoping sections nest together within the forward end of the vehicle when retracted and when extended project forwardly to extend the length of the body and thereby increase the bouyancy at the front of the vehicle. A rear extension is also provided which folds over the top of the rear portion of the vehicle when retracted. When the vehicle is prepared to enter a body of water, the front telescoping sections are extended forwardly and the rear section is pivoted to extend rearwardly to thereby provide additional front and rear located buoyancy chambers.
U.S. Pat. No. 2,075,785 issued to Van Caneghem discloses a motorcycle which has both front and rear buoyancy chambers which are retracted while the vehicle is being operated on land and which are extended to provide a high volume displacement when in the water so that the requisite buoyancy may be obtained to keep the vehicle afloat. The motorcycle has a front section wherein side walls are hinged at the lower end on each side of the front wheel. The side walls are joined at the top with what appears to be an extendable cover so that when the side walls are swung to the side, the cover encloses a volume therebetween to provide flotation at the forward end of the vehicle. Similar construction is seen at the rear of the vehicle. It should be noted that Van Caneghem does not utilize a continuous bag to enclose a flotation volume, but relies on external structure with a cover extending therebetween wherein the cover folds when the external structure is closed and extends when the structure is opened.
U.S. Pat. No. 2,967,507, Schulz, shows what is called a "carrier" which is fitted around and under a vehicle and which carries a number of inflatable air chambers located at the front, rear and sides of the vehicle. The carrier is detachable from the vehicle and is only installed when it is desired to travel across water with the vehicle.
U.S. Pat. No. 3,581,701, Gehlen, discloses an amphibious vehicle which carries auxiliary floating members as well as ramps and other structure which may be used for constructing a bridge or a ferry for transporting vehicles across a stretch of water or over a ravine as examples. This apparatus is directed more toward construction for obtaining quick transport across otherwise impassable surfaces than toward structure which will provide buoyancy for an amphibious vehicle itself. Expandible auxiliary floating members are disclosed at the sides of the vehicle. These auxiliary members are filled with air and have upper covers which appear to serve as bridge surfaces in some configurations.
U.S. Pat. No. 3,750,613, Krumsiek et al, discloses a forward and upward extending shield which is mounted at the front end of a vehicle so that as the vehicle is propelled through the water the hydraulic force against the shield tends to keep the bow of the vehicle in a raised condition. The disclosure of U.S. Pat. No. 3,983,832, Kinder describes planing skis which are attached to a vehicle and which are movable between an extended and a retracted position. It should be noted that the planing skis which are stored at the sides of the vehicle in the retracted position may include honeycomb or other similar construction which will add buoyancy to the vehicle when the skis are extended and the vehicle is in the water.